1. Field
The present disclosure relates generally to coupling tubes together. In particular, the present disclosure relates to a method and apparatus for placing a sleeve to fit a first tube to a second tube.
2. Background
A first tube may be fitted to a second tube. A first end of a first tube and a second end of a second tube may each include a fitting, such as a ferrule. Each ferrule may have an annular groove and an O-ring seated in the groove. A circumference of each O-ring may extend beyond an outer surface of the ferrule. To fit the end of the first tube to the end of the second tube, a metal sleeve, of annular cross-section, may be commonly slid over a first O-ring in a first ferrule of the first tube, and then slid over a second O-ring in a second ferrule of the second tube, such that the first and second O-rings both remain within the sleeve.
Typically, the sleeve may be moved by a technician grasping an outer face of the sleeve by hand and tugging or pushing the sleeve across the O-rings. As tube and sleeve diameters increase, a technician may need to use two hands to grasp the sleeve. It can be very difficult for a technician to keep a central axis aligned with a central axis of the tubes and O-rings while trying to move the sleeve by hand. A clamshell coupling or pipe sleeve seal may often be fastened about the sleeve to secure the sleeve to the respective ends of the first and second tubes, and to join the two tubes to function as a single extended tube.
Some sleeves are formed from thin metal that may catch on or damage the O-ring as the sleeve may be fitted over the O-ring. When the sleeve catches on the O-ring, the O-ring can also become dislodged from the annular groove. Further, if the sleeve becomes misaligned and becomes non-coaxial with the fitting, the sleeve must be removed and replaced to be coaxial with the flexible tubes.
In some cases, the sleeve may have such a large diameter (i.e., 4 inches) that it may be difficult for an installer to grasp and hold on to as it may be slid over the O-ring and fitting. The above-mentioned problems become more pronounced for larger diameter sleeves, and installation of a sleeve to fit the first tube to the second tube may take up to 4 hours. During this installation time, the O-ring may need to be re-seated or replaced and/or the sleeve may need to be removed and realigned several times.
To facilitate installing large diameter sleeves, installers have attempted to improvise with tools on-hand. Installers have used nylon scrapers and metal hammers, but this solution has not sufficiently sped up the installation process and, in some cases, has caused injuries during installation. In some conditions, damage may occur to a tube being fitted, or to other aircraft components.
Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.